Has Earth’s surface always looked this way? Why or why not?
Maps can be used to locate land and water features. Water from all over the United States runs off the land and eventually into the Mississippi River. Where the river meets the ocean, there is a delta. Maps from different time periods show that while a system can appear stable, it can actually change over time. The Mississippi delta has grown larger over thousands of years. The river has changed course several times, and at the end of the river, new land forms and other land disappears. We have a lot of questions about how new land can form at the end of a river.
